1. Field of the Invention
The present invention relates to a sealed body and a method for manufacturing the sealed body. In addition, the present invention relates to a light-emitting device.
2. Description of the Related Art
A technique of forming a highly airtight sealed body by bonding two substrates to each other with glass (hereinafter also referred to as a glass layer) obtained by melting or sintering glass frit including low-melting glass has been known. In a technique disclosed in Patent Document 1, a paste containing a binder and glass frit including low-melting glass is applied to a glass substrate along an edge of the glass substrate, the binder is removed and the glass frit is melted to form a glass layer by baking of the paste, and the glass layer is irradiated with laser light with the substrate overlapping with a counter substrate so that the substrate and the counter substrate are bonded to each other with the glass layer provided therebetween; thus, a highly airtight sealed body is formed.
A baking furnace or the like is generally used in a method for removing a binder by baking of a paste; moreover, as another method, Patent Document 2 discloses a method for gasifying a binder using laser light.
Since such a glass layer has a high gas barrier property, a sealed space can be kept away from the external atmosphere. A method for sealing with such a glass layer is used for a device including an element such as an organic EL (electroluminescence) element, an organic semiconductor element, or an organic solar cell, whose performance is rapidly decreased once the element is exposed to the air (including, moisture or oxygen).
As examples of the device including the organic EL element, a lighting device including the organic EL element as a light source, an image display device in which a thin film transistor and an organic EL element are combined, and the like can be given. Since the organic EL element can be formed in a film shape and thus easily increased in area, it is suitable for a lighting device having a planar light source, a large-sized image display device (e.g., television set), or the like. In addition, an image display device including an organic EL element needs no backlight which is necessary for liquid crystal display devices and the like; therefore, thin, lightweight, high contrast, and low power consumption display devices can be obtained.